Telephone system



Oct. 10, 1933. LANGER TELEPHONE SYSTEM Filed March 21, 1932 Patented Oct. 10, 1933 TELEPHONE SYSTEM Application March 21, 1932, Serial No. 600,284, and in Germany -March 2'7, 1931 10 Claims.

The present invention relates to a circuit arrangement for switches in telephone systems over which may be reached lines of a different trafiic direction.- I v The object of the invention is to cause speaking connections to be set up as speedily as possible oversuchswitches and with the aid of simple means, this being achieved by an impulse receiver which, when seized, is set automatically to a definite trafic direction, being associated with switching means which, when another traflic direction has been identified, facilitates the setting of the switch thereto.

An embodiment of the invention is shown in the accompanying drawing. Only the circuit details necessary for the complete understanding of the feature of the invention have been shown. The invention is not limited to the embodiment only. 4

Lines leading to another exchange are to be reached in group I over the final selector LW which is constructed as a twenty-five point rotary switch with zero position, whereas group II contains subscribers"1ines associated with the exchange in question. The line L, having the leads a, b, 0, may be assumed to extend from a call finder which hunts fora calling subscribers line in known manner. Each final selector LW is associated with a discriminator M having switch Wipers 3111 and 33111. This discriminator facilitates the change-over'of the final selector from one traffic direction to another. The final selector LW is provided with the switch wipers a--d, a contact bank brushed by the switch wiper 01 also being used for the change-over of the final selector. This contact bank is provided with the stopping positions x and y.

When a subscriber wishes to set up a connection, the call finder (not shown) is set to the subscribers connecting line when the receiver is lifted and the final selector LW seizes an idle exchange line at once. The switching operations are as follows: When the call finder has seized the connecting line, the windings I and II of relay A are connected to battery due to the loop of subscribers line being closed by means of the switch hook, with the consequence that relay A is energized. The opening of contactla removes the short circuit for the seizing relay C of the final selector. Contact 30a opens the circuit for the rotary magnet D1 of the discriminator M, while contact 1311 short circuits winding I of the slowacting relay V. Contact 35a opens the circuit for the rotary magnet D of the final selector LW. Contact-51a is located in thecircuit of the succeeding switch. Due to the short circuit for relay C being removed by means of contact 1a, said relay C is energized in the following circuit: earth, battery in the call finder- (not-shown); c -lead, winding of relay C, contact 2 to (contact of the rotary magnet D of the final selectorLW which is shown in the normal position of the final selector only), switch wiper 3d1 of the discriminator M, contact 411, earth. Relay C, by the closing of its contact 50, is placed in a locking circuit and, by closing contact '70, prepares a circuit for the rotary magnet D1 and also, by the closing-of contact 90, a circuitfor the rotary magnet D. Contact 140 closes the circuit for winding, I of relay V. This relay, however, will not be energized, since contact 13a is closed; that is to say, therelay is short circuited. A circuit for winding II of relay V is prepared over contact 80. Contact 6c closes the circuit for relay H, thus energizing this relay, which closes its contacts 10h and 11h and, at the same time, causes contact 12h to be opened. By the throwing of contact 1071., the interrupter Us is connected to the rotary magnet D of the final selectorLW in the following circuit: earth, interrupter Ue, contact 10h, d-wiper of thefinalselector LW, windingof the rotary magnet D, battery, earth. The switch is advanced from its normal position and actuated step by step over the segment of its contact bank to which the interrupter is connected over the closed contact 15p. This contact bank corresponds to group I of lines 2, e, lines leading to an exchange, When the c-wiper of the final selector LW en'- counters a free exchange line, the test relay P will be energized in known manner in the follow- UNITED STATES PATENT .oFFICEQ ing circuit: earth, closed contactQc, contact 3112,

windings II and I of "relay P, c-wiper of the final selector LW, battery, earth (to a free exchange line). The test relay P is energized and by means of-its contact 15p cuts off the circuit for the rotary magnet D and thus in known manner guards the seized exchange line against other final selectors due to the short circuiting'ofits high resistance winding II over contact 161). Con- 1 tacts 41p and 42p switch through the junction line to the final selector. I r

The subscriber may now himself, by transmit ting impulse series, set the switches in the exchange and complete the required-connection; If the first two impulse series sent out (the number of impulse series characterizing the chang'-' over is optional) indicate that the subscriber requires an internal connection, the correspond-.- ing change-over of the final selector takes place, said final selector then being setto thepcorre sponding subscribers connection by means of impulse series. The rotary magnet D1, by means of contact a of relay A, is made dependent on said impulse relay, whereas the circuit for the rotary magnet D is intermittently closed by contact a- The impulses set up by contact 35a infiuence the circuit for the rotary magnet D only when contact 2621. also is closed.

If, for example, the calling subscriber dials the digit 3, the switch wiper 3d1 sets up the following circuit for relay U1 as relay V releases after each impulse series; earth, contact 41), wiper 3d1 of the discriminator M, contact 20u1, winding of relay Ul, battery, earth. Relay U1 is energized in this circuit and remains energized over its thrown-over light contact 20u1 and the closed contact 11h to earth. The closing of contact 2lu1 prepares a circuit for relay U2. When the subscriber now dials the second digit, for example, the digit 6, relay V releases afresh after the impulse output and closes the following circuit for relay U2: earth, contact 412, switch wiper 3d1, contacts Zlul, 22u2, winding of relay U2, battery, earth; Relay U2 is energized in this circuit, remains energized over the light contact 2211 and contact 11h and, due to the opening of its contact u2, prevents further impulse series from being transmitted over the free exchange line. The throwing over of contact 25112 closes the circuit for winding II of relay U. Relay U remains energized over its contact 321; and its winding I over contact 90 to earth and closes the following circuit for the rotary magnet D of the final selector LW, over its contact 27a: earth, interrupter Ue, contact 27w, d-wiper of the final selector LW,

winding of rotary magnet D, battery, earth. The rotary magnet D is advanced in this circuit until the switch wiper d has left the corresponding 3 segment of its contact bank and encounters the contact located in front of the stopping position 3;, which contact is connected to the conductor extending to winding II of relay V. The rotary magnet D cannot be energized when winding II 1 of relay V is placed in series therewith, due to the fact that winding II of relay V has a high resistance. As soon as the d-switch-wiper of the final selector LW leaves the segment over which the interrupter Ue was connected up, the c-wiper leaves the group of exchange lines which causes the test relay P to be de-energized. This restores among others the contact 16p to normal with the result that, due to contact 261; being closed, the following circuit for the rotary magnet D of the final selector is intermittently closed when contact 35a of the impulse relay A is closed on the transmission of the succeeding impulse series: earth, contacts 9c, 16p, 2611., 352, winding of the rotary magnet D, battery, earth. Relay A not yet being energized, no operations will result. According to which group of subscribers lines the calling subscriber requires, he dials either digit 1 or digit 0. When dialling digit 1,

V he causes the final selector to be set to the stopping position m, and dialling the digit 0 to the stopping position y. The subscriber now dials the last digit, which causes the final selector LW to be set to the required subscribers line. The advance of the rotary magnet takes place in the circuit just referred to. If the required subscribers line is idle, the relay P is re-energized, which, due to the open contact 3112, cannot be energized during the impulse series, and opens the circuit for the rotary magnet D by means of its contact 16p and. by the short circuiting of its high-resistance winding sets up the guarding in the manner already described.

The required connection is now completed and conversation may take place. When the calling subscriber replaces his receiver at the end of the call, relay A releases in known manner and, by the short circuiting of relay C with the aid of contact 1a, causes said relay to be released with slow action. The opening of contact causes relay H to be deenergized. The closing of contact 12h restores the final selector LW to normal by means of the interrupter Ue independently whether it has been set to the stopping position a: or y or whether it is set to the first of the second group of subscribers lines. The discriminator returns to its original position over the multiple contact bank of the switch wiper 33111, since the interrupter Ue also is connected up over this contact wiper and contact 10h in normal position.

Instead of the group of exchange lines and the two groups of subscribers lines, a group of lines may, obviously, be connected to the contact banks of the final selector and lead to another small exchange similar to the type shown.

What is claimed is:

1. In an automatic switch having access to two groups of lines, means responsive to the seizure of the switch for causing it to select an idle line in one group, means for responding to impulses and for repeating the impulses over the selected line, and means controlled by said last means for causing the switch to abandon the selected line, take up a position in selective relation to the other line group, and wait in said position for further impulses.

2. In an automatic switch having access to two groups of lines, means responsive to the seizure of the switch for causing it to select an idle line in onegroup, means for responding to impulses and for repeating them over the selected line, means controlled by said last means for causing the switch to abandon the selected line, and means responsive to directive control for causing the switch to connect with a wanted line in the other group.

3. In an automatic switch having access to two groups of lines, means responsive to the seizure of the switch for causing it to select an idle line in one group, means for responding to a plurality of series of impulses, and means operative dependent upon the value of the first two series of impulses for causing the switch to abandon the selected line, take up a position 1211 36180? tive relation to the second line group, and wait in said position for another series of impulses.

4. In an automatic switch having access to two groups of lines, means responsive to the seizure of the switch for causing it to select an idle line in one group, means for responding to a plurality of series of impulses, and means opera tive dependent on the value of the first impulse series for rendering the switch directively operable by a subsequent impulse series to connect with a particular line in the other group.

5. In an automatic switch having access to a plurality of outlets, means for causing the switch to hunt for and connect with an idle outlet responsive to the seizure of the switch, means forv responding to impulses, and means controlled by said last means for converting the switch from a free hunting switch to a directively operable switch.

6. An automatic switch adapted to operate as a free hunting switch responsive to its seizure,

to respond to and repeat impulses, and to reoperate subsequently under directive control, all on the same call. 7

'7. An automatic switch adapted to operate initially as a free hunting switch responsive to its seizure, to respond to and repeat impulses, and, dependent upon the value of the impulses, to re-operate directively responsive to further impulses.

8. In a telephone system, an automatic switch, trunk lines and subscribers lines accessible to the switch, means for seizing the switch, means responsive to said seizure for operating the switch to hunt for and connect with a trunk line, means for transmitting series of impulses to the switch, means in the switch for repeating certain of said impulse series over the trunk line connected with, and means in the switch controlled by the value of the repeated impulse series for causing the switch to abandon said trunk and respond to a subsequent series of impulses to select a subscribers line.

9. In a telephone system, a first switch having access to two groups of lines, a second switch associated individually with the first switch, means for extending a connection to the first switch, means responsive to said connection for operating said first switch to hunt for and connect with an idle line in one group, means for transmitting impulses over said connection to the first switch, means in the first switch for repeating the impulses to the second switch and, to the connected line, means controlled by the second switch for causing said first switch to release the connected line and for rendering the second switch nonresponsive to further impulses from said repeating means.

10. A telephone system as claimed in claim 9 in which the further impulses directively set the first switch to connect with a wanted line in the other group.

MAX LANGER. 

